On Fri, Jul 17, 2009 at 11:52 PM, Rowdy Rednose <rowdy.redn...@gmx.net>wrote:
> > How can I lexically bind names like "let" does in a macro, when names > and values for those bindings are passed in? > > This here works fine when I pass a literal collection: > > (defmacro let-coll > [coll & body] > `(let ~(vec coll) ~...@body)) > > user=> (let-coll [a 11 b 22] (list b a)) > (22 11) > > Doing the same with a var doesn't work though: > > user=> (def x ['a 11 'b 22]) > #'user/x > user=> (let-coll x (list b a)) > java.lang.Exception: Unable to convert: class clojure.lang.Symbol to > Object[] (NO_SOURCE_FILE:0) > > Any ideas? > It'll be evaluating (vec 'x) during macro expansion, which gives that error. The argument x has to be evaluated for it to work, so you'd need (vec (eval x)) in there. Then you'll also need to quote when passing in a literal vector, e.g. (let-coll ['a 11 'b 12] (list b a)). --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
